Numerous techniques have been developed for getting two or more exposures of a single film unit, each exposure being directed to a particular portion of the film unit to thereby provide special indicia, background scenes and diverse subject matter. This basic concept is not new. Representative background photographic techniques in its field are discussed below.
A U.S. patent to Reed, U.S. Pat. No. 4,310,232, discloses making two exposures of the same film unit while it is in place within a camera. One of the exposures involves a background transparency overlying the film unit to provide the background desired. The other exposure involves an object before the camera.
A U.S. patent to Edelstein et al., U.S. Pat. No. 4,427,279, discloses camera structure to provide two exposures of a single film unit. The two exposures are to different sections of the film unit. One exposure is through a lens and shutter system and the other is by way of an internally structured light source directing light to the film unit through a slide which provides indicia or other instructional information on a portion of the exposed film unit. Both exposures take place simultaneously inside the same camera.
A U.S. patent to Jaffe, U.S. Pat. No. 4,655,570, is similar to the patent to Edelstein et al. mentioned above in that it divides each film unit into two sections. Each patent provides an internally mounted light source to expose one section of each film unit and a lens and shutter system to expose the other section of the film unit.
A U.S. patent to Johnson et al., U.S. Pat. No. 4,707,106, discloses a lens masking technique to obtain multiple images on a single film unit but all exposures occur after the film cassette is mounted in the camera.
A U.S. patent to Doyle, U.S. Pat. No. 4,816,848, discloses mounting an image bearing template in the focal plane opening of a film cassette to provide indicia on film units when they are exposed.
A U.S. patent to Guez, U.S. Pat. No. 4,827,291, discloses masking and exposing each frame of a roll of negative film while it is in a camera, rewinding the exposed roll, providing a different mask and exposing each frame a second time. All masking and exposures take place while the roll of film is in the camera.
A U.S. patent to Barrett, U.S. Pat. No. 4,896,176, discloses placing a transparency within a cassette overlying a film unit. Each film unit receives reflected light from a flash unit, which light reflects from the back side of an external screen through the camera lens. The reflected light exposes the film unit around its edges and thereby produces an edge design as desired by the photographer. The edge design is supplied by an overlay inside the camera between the lens and the film unit. The central portion of the film unit is simultaneously exposed to record the subject before the camera. Exposure of the film unit occurs only once when the photographer activates the shutter.
A U.S. patent to Spector, U.S. Pat. No. 4,994,832, includes a disclosure of pre-exposing a film unit at some period of time prior to the time the film unit is exposed a second time to capture the image of the desired subject. The technique used by Spector is not one of using a mask over a portion of the film unit, but rather exposing the whole film unit frame twice, first by an under-exposure based on light and timing and later by a full exposure of the primary object to be photographed.
What is not disclosed by the background information as set out above are appropriate apparatus and procedural steps for pre-exposing a series of film units with the same background or peripheral indicia on each unit during the manufacturing process 1) prior to the time the individual film units are severed from the strip or web of film and 2) before a pod of developer liquid is attached to the individual film unit for use in a conventional self developing film combination.